A high-hardness high-wear-resistance laser cladding coating powder and a method for preparing a coating

Abstract

The application discloses a high-hardness and high-wear-resistance laser cladding coating powder and a method for preparing the coating, the coating powder is obtained by uniformly mixing gas atomized Fe-RE metal original powder and hard phase powder; the coating powder comprises 91-93% of the gas atomized Fe-RE metal original powder and 7-9% of the hard phase powder in percentage by mass; the gas atomized Fe-RE metal original powder comprises the following components in percentage by mass: 27-30% of Cr, 0.18-0.25% of C, 3.0-4.0% of Si, 2.0-3.0% of B, 5.0-6.0% of Ni, 0.1-0.5% of RE, less than or equal to 0.01% of impurities, and the balance of Fe. The laser cladding coating prepared by the application has superior performance, the hardness is more than 65HRC, and the laser cladding coating has extremely strong wear resistance, so that the performance requirement of the industry on the high-quality laser cladding coating can be met, and the high-performance and cutting-edge technology requirement can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of surface repair of metal materials. Specifically, it is a kind of high hardness and high wear resistance laser cladding coating powder and a method for preparing the coating. BACKGROUND

[0002] Compared with traditional surface repair process, laser cladding technology has the advantages of no material selection limitation, small thermal stress and thermal deformation, high bonding strength, etc. In recent years, the ultra-high-speed laser cladding technology has developed rapidly, which has important advantages in saving powder, improving cladding rate, reducing deformation and ensuring metallurgical bonding strength, and has attracted attention from the industry. Laser cladding technology has been widely used in aerospace, energy and power, metallurgical machinery and other fields in recent years.

[0003] Compared with Ni-based and Co-based surface repair powders, Fe-based surface repair powders have the advantages of outstanding physical and chemical properties and low cost. At the same time, metal-ceramic composite powders can have both the toughness of metal matrix and the high hardness of ceramic particles, and have been widely used in laser cladding. However, there are large differences in physical and chemical properties between the two, which can cause poor bonding between the two, resulting in cracks, pores and other defects in the cladding layer, and the microstructure of the cladding layer is relatively coarse, and the hardness and wear resistance of the coating are poor. SUMMARY

[0004] In view of the deficiencies of the prior art, the present application provides a kind of high hardness and high wear resistance laser cladding coating powder and a method for preparing the coating, to achieve the following purposes:

[0005] Improve the hardness and wear resistance of laser cladding coating.

[0006] To solve the above technical problems, the present application provides the following technical solutions:

[0007] A kind of high hardness and high wear resistance laser cladding coating powder, the coating powder is obtained by uniformly mixing gas atomized Fe-RE metal raw powder and hard phase powder;The coating powder includes 91-93% of gas atomized Fe-RE metal raw powder and 7-9% of hard phase powder by mass percentage;The composition of the gas atomized Fe-RE metal raw powder by mass percentage is as follows: Cr is 27-30%, C is 0.18-0.25%, Si is 3.0-4.0%, B is 2.0-3.0%, Ni is 5.0-6.0%, RE is 0.1-0.5%, impurity content is less than or equal to 0.01%, and the balance is Fe.

[0008] The following is a further improvement on the above technical solutions:

[0009] The gas atomized Fe-RE metal primary powder, in terms of mass percentage, is composed of 28% of Cr, 0.22% of C, 3.1% of Si, 2.5% of B, 5.4% of Ni, 0.2% of RE, 0.01% of impurities, and 60.57% of Fe.

[0010] The RE is one or more of La, Ce and Y; and the hard phase powder is one or more of WC, TiC and SiC.

[0011] The RE is composed of La and Y, the mass percentage of La is 50%, and the mass percentage of Y is 50%.

[0012] The hard phase powder is a mixture of WC and TiC, the mass percentage of WC is 60%, and the mass percentage of TiC is 40%.

[0013] The particle size range of the gas atomized Fe-RE metal primary powder is 53-150 μm, and the particle size range of the hard phase powder is 50-150 μm.

[0014] The preparation method of the gas atomized Fe-RE metal primary powder is to use high-carbon chromium iron, bulk graphite, pure silicon, pure iron, nickel plate, boron iron and rare earth oxide as raw materials, smelt in a medium frequency furnace, and obtain the gas atomized primary powder through nitrogen atomization.

[0015] The smelting temperature is 1545-1555 ℃, the atomization temperature is 1568-1573 ℃, and the atomization pressure is 5.4-5.6 MPa.

[0016] The mass percentage of each raw material of the gas atomized Fe-RE metal primary powder is as follows: the content of high-carbon chromium iron is 51.8-52%; the content of bulk graphite is 0.38-0.42%; the content of pure silicon is 3.57-3.63%; the content of pure iron is 21.3-21.5%; the content of nickel plate is 5.3-5.5%; the content of boron iron is 16.7-16.9%; the content of La2O3 and Y2O3 is 0.28-0.31% and 0.19-0.21% respectively.

[0017] The high-hardness and high-wear-resistance laser cladding coating powder adopts a synchronous powder feeding mode, and a fiber laser is used to form a cladding layer on the surface of a substrate, and the specific steps are as follows:

[0018] (1) The metal substrate to be subjected to surface cladding is pretreated, and the coating powder is dried and then sieved;

[0019] (2) The high-hardness and high-wear-resistance metal powder is weighed according to the proportion for standby;

[0020] (3) The high-hardness and high-wear-resistance metal powder is laser cladded on the surface of the metal substrate by using a laser;

[0021] (4) heat treatment and machining.

[0022] The process parameters during the laser cladding are as follows: laser power is 2000-3000W; spot diameter is 2.5mm; cladding speed is 1000-1500mm / min; powder feeding speed is 18-30mg / s; lap rate is 60%-70%; high-purity argon is used as the protective gas, and the gas flow is 10-20L / min.

[0023] The metal base is 45 steel; 18-22kg of coating powder is cladded on the surface of the metal base per 1m 2 Metal base material surface cladding 18-22kg of coating powder.

[0024] The technical scheme of the present application achieves the following beneficial technical effects:

[0025] (1) The laser cladding coating prepared by the coating powder has superior performance, and the hardness exceeds 65HRC, and at the same time has extremely strong wear resistance, and from the cross-sectional morphology of the vertical wear direction after the friction and wear test (GB / T 12444-2006), it can be seen that the wear depth is relatively shallow, only 34.8μm, and the affected wear width is relatively small, only 1186.3μm, and the overall wear performance is relatively good,

[0026] It can meet the performance requirements of the industry for high-quality laser cladding coatings, and meet the high-performance cutting-edge technology requirements. Compared with the traditional method of preparing laser cladding coatings, the laser cladding coating powder and the preparation method of the present application are beneficial to the industrialized large-scale production of high-quality laser cladding coatings.

[0027] (2) The high-hardness and high-wear-resistance laser cladding coating powder prepared by the present application has high quality, and the loose bulk density reaches 4.57g / cm 3 , and the fluidity is 12.6s / 50g.

[0028] (3) The present application adds RE elements on the basis of the traditional Fe-based laser repair powder, which can effectively improve the powder quality, which is due to the addition of RE elements, which can remove harmful impurity elements such as O, P and S, thereby purifying the melt, and at the same time, the addition of RE elements can effectively improve the liquid Gibbs free energy of the melt, improve the atomization efficiency and quality. The addition of RE can also promote the generation of hard phase CrC in the cladding process, and at the same time inhibit its growth, thereby improving the hardness and wear resistance of the cladding coating.

[0029] (4) The present invention obtains laser cladding coating powder by uniformly mixing Fe-RE metal powder and hard phase powder through gas atomization. It can simultaneously possess the toughness of metal matrix and the high hardness of ceramic particles. The prepared coating has advantages such as high hardness and high wear resistance. Compared with conventional metal-ceramic composite coatings, the addition of RE element in the present invention effectively enhances the bonding between metal and ceramic phase in the cladding layer, thereby improving the hardness and wear resistance of the coating. Attached Figure Description

[0030] Figure 1 This is a SEM image of the gas-atomized Fe-RE metal powder in Example 1 of the present invention;

[0031] Figure 2 This is a SEM image of the hard phase powder in Example 1 of the present invention;

[0032] Figure 3 This is a metallographic microscope image of the microstructure of the laser cladding coating in Embodiment 1 of the present invention;

[0033] Figure 4 These are SEM images of the gas-atomized Fe-based metal powders in Comparative Examples 1 and 2 of this invention.

[0034] Figure 5 This is a metallographic microscope image of the microstructure of the laser cladding coating in Comparative Example 1 of the present invention;

[0035] Figure 6 This is a metallographic microscope image of the microstructure of the laser cladding coating in Comparative Example 2 of the present invention;

[0036] Figure 7 The above are bar charts showing the coating hardness of Embodiment 1, Comparative Example 1, and Comparative Example 2 of the present invention.

[0037] Figure 8 Metallographic microscope images of the cross-sectional morphology of the coatings in the perpendicular wear direction of Embodiment 1, Comparative Example 1, and Comparative Example 2 of the present invention.

[0038] in Figure 8 a is a metallographic microscope image of the cross-sectional morphology of the coating in Example 1 in the direction perpendicular to the wear direction; Figure 8 b is a metallographic microscope image of the cross-sectional morphology of the coating in the perpendicular wear direction of Comparative Example 1; Figure 8 c is a metallographic microscope image of the cross-sectional morphology of the coating in the perpendicular wear direction of Comparative Example 2.

[0039] Figure 8 The coating shown in figure a incorporates rare earth elements and hard phase particles, resulting in a uniformly distributed hard and ceramic phase, thus improving the material's wear resistance. Figure 8 The coating shown in b contains only hard phase particles, and only a uniform hard phase structure was observed in its structure. Its hardness and wear resistance are both reduced compared to Example 1.Figure 8 The coating shown in c has no hard phase particles in the microstructure, and the hardness and wear resistance are poor due to the absence of hard phase and rare earth. DETAILED DESCRIPTION

[0040] Example 1: A high-hardness and high-wear-resistance laser cladding coating powder

[0041] The coating powder is obtained by uniformly mixing gas-atomized Fe-RE metal primary powder and hard phase powder, and includes 92% of the gas-atomized Fe-RE metal primary powder and 8% of the hard phase powder in terms of mass percentage.

[0042] The particle size range of the gas-atomized Fe-RE metal primary powder is 53-150 μm, and the particle size range of the hard phase powder is 50-150 μm.

[0043] The gas-atomized Fe-RE metal primary powder has a composition of 28% of Cr, 0.22% of C, 3.1% of Si, 2.5% of B, 5.4% of Ni, 0.2% of RE, 0.01% of impurities, and 60.57% of Fe in terms of mass percentage.

[0044] The RE is composed of La and Y, and the mass percentage of La is 50%, and the mass percentage of Y is 50%.

[0045] The hard phase powder is a mixture of WC and TiC, and the mass percentage of WC is 60%, and the mass percentage of TiC is 40%.

[0046] The high-hardness and high-wear-resistance laser cladding coating powder prepared in the example has a loose bulk density of 4.57 g / cm 3 , and a fluidity of 12.6 s / 50 g.

[0047] The gas-atomized Fe-RE metal primary powder in the example is prepared by using high-carbon chromium iron, bulk graphite, pure silicon, pure iron, nickel plate, boron iron, and rare earth oxides as raw materials, smelting in a medium-frequency furnace at a smelting temperature of 1550 ℃, and obtaining the gas-atomized primary powder by nitrogen atomization at an atomization temperature of 1570 ℃ and an atomization pressure of 5.5 MPa.

[0048] The indexes of the raw materials of the gas-atomized Fe-RE metal primary powder are as follows: the C content of the high-carbon chromium iron is 0.3%, the Cr content is 58.3%, and the Fe content is 40.1%; the C content of the bulk graphite is ≥99.9%; the Si content of the pure silicon is greater than 99%; the Fe content of the pure iron is ≥99.9%; the Ni content of the nickel plate is 99.96%; the B content of the boron iron is 17.1%, and the Fe content is 81.77%; and the rare earth oxides are La2O3 and Y2O3.

[0049] The mass percentage of each raw material of the gas atomized Fe-RE metal powder is as follows: high-carbon chromium iron content is 51.9%; block graphite content is 0.4%; pure silicon content is 3.6%; pure iron content is 21.4%; nickel plate content is 5.4%; boron iron content is 16.8%; La2O3 and Y2O3 content is 0.3% and 0.2% respectively.

[0050] The apparent density of the prepared gas atomized Fe-RE metal powder is 4.51 g / cm 3 , and the flowability is 13.0 s / 50 g.

[0051] The micro-morphology of the gas atomized Fe-RE metal powder prepared in the embodiment is shown in Figure 1 It can be observed that after adding the RE element, the prepared powder has very high sphericity, the powder surface is smooth, the number of satellite powder is small, and the powder performance is excellent. Figure 2 The micro-morphology of the hard phase particle is shown in

[0052] The application also provides a preparation method of a high-hardness and high-wear-resistance laser cladding coating.

[0053] (1) The metal substrate to be surface cladded is pretreated, including surface grinding, polishing and oil removal treatment, the high-hardness and wear-resistance metal powder is dried at 150 DEG C for 0.5 h, and after drying, the powder is sieved;

[0054] (2) The reasonable high-hardness and wear-resistance metal powder is weighed according to the proportion for standby;

[0055] (3) The high-hardness and wear-resistance metal powder is laser cladded on the surface of the metal substrate by using laser, 20 kg of the high-hardness and wear-resistance metal powder is needed for the surface of the metal substrate per 1 m 2 .

[0056] (4) The metal substrate is heat treated and machined after laser cladding.

[0057] The metal substrate in step (1) is 45 steel.

[0058] The process parameters during laser cladding in step (3) are as follows: laser power is 2500 W; spot diameter is 2.5 mm; cladding speed is 16.7 mm / s; powder feeding speed is 18 mg / s; lap rate is 60%; high-purity argon is used as the protective gas, and the gas flow is 12 L / min.

[0059] The heat treatment temperature in step (4) is 200 DEG C, and the heat treatment time is 0.5 h.

[0060] The average hardness of the high-hardness and high-wear-resistance laser cladding coating prepared in the embodiment is 66.7 HRC, and the coating has extremely high wear resistance, and the thickness of the cladding coating after turning and grinding is 0.5 mm.

[0061] The hardness in the embodiment is measured by a Rockwell hardness tester, and 7 points are measured and averaged; the wear test is performed according to GB / T 12444-2006. Note: The wear resistance is determined by the cross-sectional wear amount after the friction and wear test, that is, the smaller the wear amount, the better the wear resistance.

[0062] The microstructure of the laser cladding coating of the embodiment is shown in Figure 3 As can be seen from the figure, the cladding coating is composed of uniform equiaxed crystals, and hard phase particles are embedded in the crystals. The hard phase in the coating is composed of the added hard phase powder and the endogenous hard phase, and a certain size gradient level is formed. Due to the addition of RE elements, the size of the hard phase particles is smaller and uniformly distributed, and the size is only 10-60 μm, which greatly improves the hardness and wear resistance of the coating to a certain extent. After the addition of RE elements, part of the rare earth phase is generated, as shown by the black particles in the figure, which can effectively refine the microstructure of the cladding layer, which also plays a certain role in improving the hardness and wear resistance of the coating. Figure 8 As shown in a, it is the cross-sectional morphology of the embodiment after the friction and wear test (GB / T 12444-2006) in the vertical wear direction. It can be seen that the wear depth is relatively shallow, only 34.8 μm, and the affected wear width is small, only 1186.3 μm, and the overall wear performance is relatively good.

[0063] Comparative Example 1

[0064] The difference between the comparative example 1 and the embodiment 1 is that the laser cladding coating powder prepared does not contain rare earth elements. The specific preparation method is as follows:

[0065] The laser cladding coating powder in the comparative example 1 is obtained by uniformly mixing gas-atomized Fe-based metal primary powder and hard phase powder. In terms of mass percentage, it includes 92% of gas-atomized Fe-based metal primary powder and 8% of hard phase powder.

[0066] The particle size range of the gas-atomized Fe-based metal primary powder is 53-150 μm; the particle size range of the hard phase powder is 50-150 μm.

[0067] The specific composition of the gas-atomized Fe-based metal primary powder prepared in the comparative example 1 is as follows: Cr is 27.5%, C is 0.21%, Si is 3.1%, B is 2.52%, Ni is 5.3%, the impurity content is 0.015%, and the balance is Fe.

[0068] The gas atomized Fe-based metal primary powder in the present comparative example 1 does not contain RE elements.

[0069] The hard phase powder comprises a mixture of WC and TiC, wherein the mass percentage of WC is 60%, and the mass percentage of TiC is 40%.

[0070] The loose bulk density of the laser cladding coating powder prepared in the present comparative example 1 is 4.39 g / cm 3 , and the flowability is 14.4 s / 50 g.

[0071] The gas atomized Fe-based metal primary powder in the present comparative example 1 is prepared as follows: high-carbon chromium iron, bulk graphite, pure silicon, pure iron, nickel plate and boron iron are used as raw materials, and smelting is performed in a medium-frequency furnace at a smelting temperature of 1550℃; the gas atomized primary powder is obtained by nitrogen atomization at an atomization temperature of 1570℃ and an atomization pressure of 5.5 MPa.

[0072] The C content in the high-carbon chromium iron is 0.3%, the Cr content is 58.3%, and the Fe content is 40.1%; the C content in the bulk graphite is ≥99.9%; the Si content in the pure silicon is greater than 99%; the Fe content in the pure iron is ≥99.9%; the Ni content in the nickel plate is 99.96%; the B content in the boron iron is 17.1%, and the Fe content is 81.77%.

[0073] The mass percentage of each raw material in the gas atomized Fe-based metal primary powder is as follows: the high-carbon chromium iron content is 51.9%; the bulk graphite content is 0.4%; the pure silicon content is 3.6%; the pure iron content is 21.9%; the nickel plate content is 5.4%; and the boron iron content is 16.8%.

[0074] The micro-morphology of the gas atomized Fe-based metal primary powder prepared in the present comparative example 1 is shown in Figure 4 As can be observed, the powder has a relatively high sphericity, but compared with the high-hardness and high-wear-resistance laser cladding coating powder in the present example 1, no RE element is added during the powder preparation of the present comparative example 1, the liquidus line of the metal melt is raised, thereby reducing the overheating degree during the powder atomization process, resulting in a significant increase in the number of satellite powders, a decrease in the surface finish of the powder, and poor comprehensive performance of the powder.

[0075] The present application also provides a preparation method of a laser cladding coating, which adopts a synchronous powder feeding mode and utilizes a fiber laser to form a cladding layer on the surface of a substrate, and the specific steps are as follows:

[0076] (1) The metal substrate to be subjected to surface cladding is pretreated, including surface grinding, polishing and oil removal treatment, and the high-hardness and wear-resistant metal powder is dried at 150℃ for 0.5 h, and then sieved after drying;

[0077] (2) Weigh a reasonable amount of high-hardness wear-resistant metal powder according to the proportion for standby;

[0078] (3) Laser cladding high-hardness wear-resistant metal powder on the surface of the metal substrate, 20 kg of high-hardness wear-resistant metal powder is needed for each 1 m2 of the surface of the metal substrate; 2 Metal substrate surface needs 20 kg of high-hardness wear-resistant metal powder;

[0079] (4) After laser cladding, the metal substrate is subjected to heat treatment and turning and grinding processing.

[0080] The metal substrate in step (1) is 45 steel.

[0081] The process parameters during laser cladding in step (3) are as follows: laser power is 2500 W; spot diameter is 2.5 mm; cladding speed is 16.7 mm / s; powder feeding speed is 18 mg / s; overlap rate is 60%; high-purity argon is used as protective gas, and the gas flow is 12 L / min.

[0082] The heat treatment temperature in step (4) is 200℃, and the heat treatment time is 0.5 h.

[0083] The average hardness of the laser cladding coating prepared in Comparative Example 1 is 57.3 HRC, which is lower than that of the high-hardness and high-wear-resistance laser cladding coating powder in Example 1. The microstructure of the laser cladding coating of Comparative Example 1 is shown in FIG. 2B, and the microstructure of the laser cladding coating of Comparative Example 1 is composed of coarse dendrites, and only a small amount of cellular crystals in the microstructure, which indicates that when only hard phase is added, the microstructure of the laser cladding coating is not refined, which has little effect on the improvement of the hardness and wear resistance of the coating. Figure 5 Figure 8 FIG. 2C shows the cross-sectional morphology of the laser cladding coating of Comparative Example 1 after the friction and wear test, and it can be seen that the wear depth is relatively deep, which is 39.5 μm, and the affected wear width is relatively long, which is 1354.7 μm, and the overall wear performance is poor. In the figure, only the substrate and the white hard phase particles added can be observed, and the size of the hard phase is relatively large, which is about 80 μm, which has little effect on the improvement of the wear resistance of the coating.

[0084] Compared with Example 1, the powder morphology of Comparative Example 1 is poor, and the impurity content increases, the microstructure of the cladding coating is relatively coarse, the hardness of the cladding coating is relatively low, and the wear resistance of the cladding coating is poor. This shows that on the basis of gas-atomized Fe-based metal powder, the addition of rare earth elements can significantly improve the microstructure of the cladding coating, so that it is refined, and the rare earth elements can effectively increase the amount of hard phase in the microstructure of the cladding coating, reduce the size of the hard phase particles and make the distribution more uniform, improve the hardness and wear resistance of the cladding coating.

[0085] Comparative Example 2

[0086] ​The difference between the comparative example 2 and the examples is that the laser cladding coating powder prepared does not contain rare earth elements and hard phase.

[0087] The laser cladding coating powder in the comparative example 2 is an aerosolized Fe-based metal primary powder, and the particle size range of the aerosolized Fe-based metal primary powder is 53-150 μm.

[0088] The aerosolized Fe-based metal primary powder used in the comparative example 2 is the same as that used in the comparative example 1.

[0089] The bulk density of the laser cladding coating powder prepared in the comparative example 2 is 4.26 g / cm 3 , and the flowability is 15.7 s / 50 g.

[0090] The method for preparing the laser cladding coating is the same as that in the comparative example 1.

[0091] The average hardness of the laser cladding coating prepared in the comparative example 2 is only 48.2 HRC, which is much lower than the high-hardness and high-wear-resistance laser cladding coating powder and the method for preparing the same in the example 1. The microstructure of the laser cladding coating in the comparative example 2 is shown in FIG. 6, and it can be seen that the cladding coating in the comparative example 2 is composed of coarse dendrites, and no cellular crystal structure is observed in the microstructure, which indicates that the number of heterogeneous points is small during the laser cladding process, making it difficult for the crystal grains to nucleate, and the crystal grains grow rapidly into coarse dendrites. Figure 6 Figure 8 FIG. 7 shows the cross-sectional morphology of the comparative example cladding coating after the friction and wear test in the vertical wear direction, and it can be seen that the wear depth is relatively deep, being 52.7 μm, and the affected wear width is relatively long, being 1818.2 μm, and the overall wear performance is poor. Moreover, no hard phase is observed in the microstructure.

[0092] Compared with the example 1, the powder morphology of the comparative example 2 is poor, the cladding coating microstructure is relatively coarse, the cladding coating hardness is low, and the cladding coating wear resistance is extremely poor. This indicates that on the basis of the aerosolized Fe-based metal primary powder, the design of adding rare earth elements and hard phase particles can significantly improve the microstructure of the cladding coating, making it refined, and the rare earth elements can effectively increase the number of hard phases in the cladding coating microstructure, improving the hardness and wear resistance of the cladding coating.

[0093] Obviously, the above examples are merely examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. Here, it is not necessary and impossible to enumerate all the embodiments. The changes or variations derived therefrom are still within the protection scope of the patent application claims.​

Claims

1. A high-hardness, high-wear-resistant laser cladding coating powder, characterized in that, The coating powder is obtained by uniformly mixing gas-atomized Fe-RE metal raw powder and hard phase powder; the coating powder, by mass percentage, comprises 91-93% gas-atomized Fe-RE metal raw powder and 7-9% hard phase powder; the gas-atomized Fe-RE metal raw powder, by mass percentage, has the following composition: Cr 27-30%, C 0.18-0.25%, Si 3.0-4.0%, B 2.0-3.0%, Ni 5.0-6.0%, RE 0.1-0.5%, impurity content less than or equal to 0.01%, and the balance being Fe; The RE is composed of La and Y, and the mass ratio of La to Y is 1:1; The hard phase powder is composed of WC and TiC, and the mass ratio of WC to TiC is 3:2; The preparation method of the gas-atomized Fe-RE metal raw powder is to use high-carbon ferrochrome, bulk graphite, pure silicon, pure iron, nickel plate, ferroboron and rare earth oxides as raw materials, smelt them in a medium frequency furnace, and obtain the gas-atomized raw powder by nitrogen atomization. The smelting temperature is 1545-1555℃, the atomization temperature is 1568-1573℃, and the atomization pressure is 5.4-5.6MPa.

2. The high-hardness, high-wear-resistant laser cladding coating powder according to claim 1, characterized in that, The atomized Fe-RE metal powder has the following composition by mass percentage: Cr 28%, C 0.22%, Si 3.1%, B 2.5%, Ni 5.4%, RE 0.2%, impurity content 0.01%, and Fe 60.57%.

3. The high-hardness, high-wear-resistant laser cladding coating powder according to claim 1, characterized in that, The particle size range of the gas-atomized Fe-RE metal powder is 53-150 μm; the particle size range of the hard phase powder is 50-150 μm.

4. The high-hardness, high-wear-resistant laser cladding coating powder according to claim 1, characterized in that, The gas-atomized Fe-RE metal powder comprises the following raw materials in the following mass percentages: high-carbon ferrochrome content 51.8-52%; bulk graphite content 0.38-0.42%; pure silicon content 3.57-3.63%; pure iron content 21.3-21.5%; nickel plate content 5.3-5.5%; ferroboron content 16.7-16.9%; and La2O3 and Y2O3 contents of 0.28-0.31% and 0.19-0.21%, respectively.

5. A method for preparing a coating using the high-hardness, high-wear-resistant laser cladding coating powder as described in claim 1, characterized in that: The high-hardness, high-wear-resistant laser cladding coating powder is fed using a synchronous powder feeding method, and a cladding layer is formed on the surface of a metal substrate using a fiber laser. The specific steps are as follows: (1) Pre-treat the metal substrate by drying the coating powder and then sieving it; (2) Weigh out the high-hardness, wear-resistant metal powder according to the proportion and set aside; (3) Using a laser to laser-fuse high-hardness, wear-resistant metal powder onto the surface of a metal substrate; (4) Heat treatment and turning / grinding.

6. The preparation method according to claim 5, characterized in that: The laser cladding process parameters are as follows: laser power of 2000-3000W; spot diameter of 2.5mm; cladding speed of 1000-1500mm / min; powder feeding speed of 18-30mg / s; overlap rate of 60%-70%; high-purity argon is used as the protective gas, and the gas flow rate is 10-20L / min.

7. The preparation method according to claim 5, characterized in that: The metal substrate is 45 steel; per 1m 2 18-22 kg of coating powder is fused onto the surface of a metal substrate.

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